Release 4.11 net/sctp/chunk.c

/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2003, 2004
 *
 * This file is part of the SCTP kernel implementation
 *
 * This file contains the code relating the chunk abstraction.
 *
 * This SCTP implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Sridhar Samudrala     <sri@us.ibm.com>
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

/* This file is mostly in anticipation of future work, but initially
 * populate with fragment tracking for an outbound message.
 */

/* Initialize datamsg from memory. */


static void sctp_datamsg_init(struct sctp_datamsg *msg)
{
	atomic_set(&msg->refcnt, 1);
	msg->send_failed = 0;
	msg->send_error = 0;
	msg->can_delay = 1;
	msg->expires_at = 0;
	INIT_LIST_HEAD(&msg->chunks);
}

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45
84.91%
3
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Vladislav Yasevich
6
11.32%
1
16.67%
Sridhar Samudrala
2
3.77%
2
33.33%
Total
53
100.00%
6
100.00%

/* Allocate and initialize datamsg. */


static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
{
	struct sctp_datamsg *msg;
	msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
	if (msg) {
		sctp_datamsg_init(msg);
		SCTP_DBG_OBJCNT_INC(datamsg);
	}
	return msg;
}

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44
91.67%
1
25.00%
Li Zefan
2
4.17%
1
25.00%
Daniel Borkmann
1
2.08%
1
25.00%
Al Viro
1
2.08%
1
25.00%
Total
48
100.00%
4
100.00%



void sctp_datamsg_free(struct sctp_datamsg *msg)
{
	struct sctp_chunk *chunk;

	/* This doesn't have to be a _safe vairant because
         * sctp_chunk_free() only drops the refs.
         */
	list_for_each_entry(chunk, &msg->chunks, frag_list)
		sctp_chunk_free(chunk);

	sctp_datamsg_put(msg);
}

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1
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/* Final destructruction of datamsg memory. */


static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
{
	struct list_head *pos, *temp;
	struct sctp_chunk *chunk;
	struct sctp_sock *sp;
	struct sctp_ulpevent *ev;
	struct sctp_association *asoc = NULL;
	int error = 0, notify;

	/* If we failed, we may need to notify. */
	notify = msg->send_failed ? -1 : 0;

	/* Release all references. */
	list_for_each_safe(pos, temp, &msg->chunks) {
		list_del_init(pos);
		chunk = list_entry(pos, struct sctp_chunk, frag_list);
		/* Check whether we _really_ need to notify. */
		if (notify < 0) {
			asoc = chunk->asoc;
			if (msg->send_error)
				error = msg->send_error;
			else
				error = asoc->outqueue.error;

			sp = sctp_sk(asoc->base.sk);
			notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
							    &sp->subscribe);
		}

		/* Generate a SEND FAILED event only if enabled. */
		if (notify > 0) {
			int sent;
			if (chunk->has_tsn)
				sent = SCTP_DATA_SENT;
			else
				sent = SCTP_DATA_UNSENT;

			ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
							    error, GFP_ATOMIC);
			if (ev)
				sctp_ulpq_tail_event(&asoc->ulpq, ev);
		}

		sctp_chunk_put(chunk);
	}

	SCTP_DBG_OBJCNT_DEC(datamsg);
	kfree(msg);
}

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Jon Grimm
213
97.71%
4
66.67%
Sridhar Samudrala
4
1.83%
1
16.67%
Arnaldo Carvalho de Melo
1
0.46%
1
16.67%
Total
218
100.00%
6
100.00%

/* Hold a reference. */


static void sctp_datamsg_hold(struct sctp_datamsg *msg)
{
	atomic_inc(&msg->refcnt);
}

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Jon Grimm
18
94.74%
1
50.00%
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1
5.26%
1
50.00%
Total
19
100.00%
2
100.00%

/* Release a reference. */


void sctp_datamsg_put(struct sctp_datamsg *msg)
{
	if (atomic_dec_and_test(&msg->refcnt))
		sctp_datamsg_destroy(msg);
}

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25
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25
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1
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/* Assign a chunk to this datamsg. */


static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk)
{
	sctp_datamsg_hold(msg);
	chunk->msg = msg;
}


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Jon Grimm
26
96.30%
1
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Sridhar Samudrala
1
3.70%
1
50.00%
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27
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2
100.00%

/* A data chunk can have a maximum payload of (2^16 - 20).  Break
 * down any such message into smaller chunks.  Opportunistically, fragment
 * the chunks down to the current MTU constraints.  We may get refragmented
 * later if the PMTU changes, but it is _much better_ to fragment immediately
 * with a reasonable guess than always doing our fragmentation on the
 * soft-interrupt.
 */


struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
					    struct sctp_sndrcvinfo *sinfo,
					    struct iov_iter *from)
{
	size_t len, first_len, max_data, remaining;
	size_t msg_len = iov_iter_count(from);
	struct list_head *pos, *temp;
	struct sctp_chunk *chunk;
	struct sctp_datamsg *msg;
	int err;

	msg = sctp_datamsg_new(GFP_KERNEL);
	if (!msg)
		return ERR_PTR(-ENOMEM);

	/* Note: Calculate this outside of the loop, so that all fragments
         * have the same expiration.
         */
	if (asoc->peer.prsctp_capable && sinfo->sinfo_timetolive &&
	    (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) ||
	     !SCTP_PR_POLICY(sinfo->sinfo_flags)))
		msg->expires_at = jiffies +
				  msecs_to_jiffies(sinfo->sinfo_timetolive);

	/* This is the biggest possible DATA chunk that can fit into
         * the packet
         */
	max_data = asoc->pathmtu -
		   sctp_sk(asoc->base.sk)->pf->af->net_header_len -
		   sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk);
	max_data = SCTP_TRUNC4(max_data);

	/* If the the peer requested that we authenticate DATA chunks
         * we need to account for bundling of the AUTH chunks along with
         * DATA.
         */
	if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
		struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);

		if (hmac_desc)
			max_data -= SCTP_PAD4(sizeof(sctp_auth_chunk_t) +
					      hmac_desc->hmac_len);
	}

	/* Check what's our max considering the above */
	max_data = min_t(size_t, max_data, asoc->frag_point);

	/* Set first_len and then account for possible bundles on first frag */
	first_len = max_data;

	/* Check to see if we have a pending SACK and try to let it be bundled
         * with this message.  Do this if we don't have any data queued already.
         * To check that, look at out_qlen and retransmit list.
         * NOTE: we will not reduce to account for SACK, if the message would
         * not have been fragmented.
         */
	if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
	    asoc->outqueue.out_qlen == 0 &&
	    list_empty(&asoc->outqueue.retransmit) &&
	    msg_len > max_data)
		first_len -= SCTP_PAD4(sizeof(sctp_sack_chunk_t));

	/* Encourage Cookie-ECHO bundling. */
	if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
		first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;

	/* Account for a different sized first fragment */
	if (msg_len >= first_len) {
		msg->can_delay = 0;
		SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
	} else {
		/* Which may be the only one... */
		first_len = msg_len;
	}

	/* Create chunks for all DATA chunks. */
	for (remaining = msg_len; remaining; remaining -= len) {
		u8 frag = SCTP_DATA_MIDDLE_FRAG;

		if (remaining == msg_len) {
			/* First frag, which may also be the last */
			frag |= SCTP_DATA_FIRST_FRAG;
			len = first_len;
		} else {
			/* Middle frags */
			len = max_data;
		}

		if (len >= remaining) {
			/* Last frag, which may also be the first */
			len = remaining;
			frag |= SCTP_DATA_LAST_FRAG;

			/* The application requests to set the I-bit of the
                         * last DATA chunk of a user message when providing
                         * the user message to the SCTP implementation.
                         */
			if ((sinfo->sinfo_flags & SCTP_EOF) ||
			    (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
				frag |= SCTP_DATA_SACK_IMM;
		}

		chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag,
						 0, GFP_KERNEL);
		if (!chunk) {
			err = -ENOMEM;
			goto errout;
		}

		err = sctp_user_addto_chunk(chunk, len, from);
		if (err < 0)
			goto errout_chunk_free;

		/* Put the chunk->skb back into the form expected by send.  */
		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr -
				       chunk->skb->data);

		sctp_datamsg_assign(msg, chunk);
		list_add_tail(&chunk->frag_list, &msg->chunks);
	}

	return msg;

errout_chunk_free:
	sctp_chunk_free(chunk);

errout:
	list_for_each_safe(pos, temp, &msg->chunks) {
		list_del_init(pos);
		chunk = list_entry(pos, struct sctp_chunk, frag_list);
		sctp_chunk_free(chunk);
	}
	sctp_datamsg_put(msg);

	return ERR_PTR(err);
}

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Jon Grimm
221
40.04%
3
13.04%
Vladislav Yasevich
135
24.46%
4
17.39%
Marcelo Ricardo Leitner
91
16.49%
4
17.39%
Xin Long
40
7.25%
3
13.04%
Wei Yongjun
25
4.53%
1
4.35%
Tommi Rantala
24
4.35%
2
8.70%
Eric W. Biedermann
9
1.63%
1
4.35%
Al Viro
3
0.54%
1
4.35%
Hideaki Yoshifuji / 吉藤英明
1
0.18%
1
4.35%
Florian Westphal
1
0.18%
1
4.35%
Wang Weidong
1
0.18%
1
4.35%
Eric Dumazet
1
0.18%
1
4.35%
Total
552
100.00%
23
100.00%

/* Check whether this message has expired. */


int sctp_chunk_abandoned(struct sctp_chunk *chunk)
{
	if (!chunk->asoc->peer.prsctp_capable)
		return 0;

	if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) &&
	    time_after(jiffies, chunk->msg->expires_at)) {
		if (chunk->sent_count)
			chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
		else
			chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
		return 1;
	} else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&
		   chunk->sent_count > chunk->sinfo.sinfo_timetolive) {
		chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
		return 1;
	} else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) &&
		   chunk->msg->expires_at &&
		   time_after(jiffies, chunk->msg->expires_at)) {
		return 1;
	}
	/* PRIO policy is processed by sendmsg, not here */

	return 0;
}

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Xin Long
150
92.02%
6
75.00%
Jon Grimm
12
7.36%
1
12.50%
Sridhar Samudrala
1
0.61%
1
12.50%
Total
163
100.00%
8
100.00%

/* This chunk (and consequently entire message) has failed in its sending. */


void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
{
	chunk->msg->send_failed = 1;
	chunk->msg->send_error = error;
}
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Jon Grimm
28
96.55%
1
50.00%
Sridhar Samudrala
1
3.45%
1
50.00%
Total
29
100.00%
2
100.00%

Overall Contributors
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Tokens
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CommitProp
Jon Grimm
666
54.91%
4
10.53%
Xin Long
224
18.47%
7
18.42%
Vladislav Yasevich
141
11.62%
4
10.53%
Marcelo Ricardo Leitner
91
7.50%
4
10.53%
Wei Yongjun
25
2.06%
1
2.63%
Tommi Rantala
24
1.98%
2
5.26%
Sridhar Samudrala
10
0.82%
3
7.89%
Eric W. Biedermann
9
0.74%
1
2.63%
Joe Perches
7
0.58%
1
2.63%
Al Viro
4
0.33%
2
5.26%
Tejun Heo
3
0.25%
1
2.63%
Li Zefan
2
0.16%
1
2.63%
Wang Weidong
1
0.08%
1
2.63%
Eric Dumazet
1
0.08%
1
2.63%
Florian Westphal
1
0.08%
1
2.63%
Arnaldo Carvalho de Melo
1
0.08%
1
2.63%
Hideaki Yoshifuji / 吉藤英明
1
0.08%
1
2.63%
Jeff Kirsher
1
0.08%
1
2.63%
Daniel Borkmann
1
0.08%
1
2.63%
Total
1213
100.00%
38
100.00%
Directory: net/sctp

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